Barrel jet cleaning machine



A. SCHNETZER BARREL JET CLEANING MACHINE July 3, 1962 Filed March 14, 1960 INVENTOR. Alfr ld Schnetzer July 3, 1962 A. SCHNETZER 3,041,786

BARREL JET CLEANING MACHINE Filed March 14, 1960 4 Sheets-Sheet 2 INVENTOR. Alfred Schnerzer awhad aw July 3, 1962 A. SCHNETZER 3,041,786

BARREL JET CLEANING MACHINE Filed March 14, 1960 4 Sheets-Sheet 3 if 0 0 O O 0 O O B O O O O E n u c c o o o o o c o a c- INVENTOR. Alfred Schnetzer @5 4 QWA? yaw July 3, 1962 A. SCHNETZER 3,041,786

BARREL JET CLEANING MACHINE Filed March 14, 1960 4 Sheets-Sheet 4 Fig.5

INVENTOR. Alfred Schnetzer wha yw United atent 3,041,786 BARREL JET CLEANING MACHINE Alfred Schnetzer, Schatfhausen, Switzerland Filed Mar. 14, 1960, Ser. No. 14,903 7 Claims. (Cl. 519) This invention relates to an improved barrel type blast finishing machine, of the type employing revolving feed belts disclosed for example in U.S.A. Patent No. 2,909,012.

Such machines have previously been suitable to handle only certain kinds of workpieces; namely, those which do not suffer damage when being carried and tumbled about on a feed belt. Fragile and awkwardly shaped workpieces cannot be satisfactorily processed in such machines, and therefore workpieces of this kind are usually treated on the so-called table blast type machines such as employ rotating tables to support and present the workpieces at different angles to the blast jet. Hence, in many factories two machines of these different types are required, and in relatively small factories it usually happens that both such machines cannot be economically exploited.

The object of the present invention is to provide a single machine of novel form, economically combining the features of the barrel and table type machines. The invention is characterized in that a blast chamber is provided with an endless barrel type tumble belt running under laterally spaced end discs, and a removable supporting element on which a revolving table and drive means therefor are mounted; the drive means being adapted for driving connection with one of the end discs of the tumble belt mechanism, so that, as a result of this connection, a rotary motion is transmitted to the table.

In the accompanying drawing:

FIG. 1 is a vertical section through a machine of the invention;

FIG. 2 is a horizontal section taken along the line II-II of the machine of FIG. 1;

FIG. 3 is a transverse vertical section taken along line III-III through the machine of FIG. 1;

FIG. 4 corresponds to FIG. 1, but shows another method for mounting the table;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 corresponds to FIGS. 1, 4, but shows still another method for mounting the table;

FIG. 7 is a sectional view taken along line VIVI of FIG. 6;

FIGS. 8, 9, correspond to FIGS. 1, 2, but show use of an intermediate gear device for driving the table; and

FIG. is a detailed sectional view, on enlarged scale, taken along line XX of FIG. 9.

As shown in the drawing herewith, a machine may be constructed in accord with the invention to include a casing or cabinet 1 in which is mounted a workpiece supporting feed belt 2 which is mounted upon guide rollers 3, 4, 5, and arranged to train beneath a pair of laterally spaced disc-like side plates 6, 6. Power is supplied to either of the guide roller or side plate arrangements, to cause the feed belt 2 to rotate normally in counter-clockwise direction as viewed in FIG. 1 of the drawing herewith. Thus, workpieces to be cleaned or otherwise surfaceblasted may be loaded into the cradle portion of the feed belt to the left of the roller 3 as viewed in FIG. 1, whereupon the counter-clockwise rotation of the feed belt will cause the workpieces to be continuously pulled to the left and thence upwardly toward the roller 5 until such time as the natural angle of repose is exceeded whereupon the workpieces will tumble forwardly and downwardly on top of the underlying workpieces.

Throughout the operation the workpieces are subjected to blast of abrasive or other media through a jet inlet opening 7 formed in the casing 1, as explained in the above referred to Patent No. 2,909,012. Thus it will be appreciated that workpieces loaded upon the belt 2 behind the position of the roller 3 will be thereby subjected to a blast treatment from the device 7 while being continuously tumbled so as to present to the blast stream constantly changing surface portions of the workpieces. Direction of rotation of the belt 2 is reversed when it is desired to unload the treated workpieces, so that the workpieces will thereupon be discharged over the roller 3- into a suitable receptacle, as guided for example by an apron as indicated at 23 (FIG. 1).

The casing 1 is provided with an access door as indicated at 8 which in the form of the invention shown in FIGS. 1-3 is provided with vertically aligned bearings 9, 9, adapted to receive a pivot pin portion 10 of a support arm 11 which is dimensioned to reach into the interior of the casing between the positions of the end plates 6, 6. The arm 11. terminates therein with a vertically directed stub axle portion 12 which rotatably supports thereon the hub portion 13 of a table device having integrally formed therewith a drive wheel 14 and a bracket 15 adapted to detachably support a workpiece load basket 16. The basket 16 is of open top construction and slip-fit mounted within the bracket 15 so as to be readily removable.

Some suitable arrangement is provided for biasing the wheel portion 14 of the device to bear in friction-driving relation against one of the end discs 6 so as to derive power therefrom for rotating the workpiece carrying basket 16. As shown in FIGS. 1-3, such an arrangement may comprise a bracket 17 extending from the door 8, and a tension spring 19 extending therefrom into connection with a bracket 18 attached to the support arm 11; the parts being so arranged that the tension of the spring 19 causes the friction wheel 14 to be constantly biased into driving bearing relation against one of the discs 6 (FIG. 2). The mechanism is so arranged that the friction wheel 14 contacts the end disc 6 at a distance offset from the center of rotation of the end disc, such as indicated for example at 20 in FIG. 1. Thus, it will be appreciated that rotation of the end disc 6 will cause simultaneous rotation of the workpiece carrying basket 16, whereby workpieces placed in the basket 16 will be caused to move about under the blast issuing from the jet opening 7, so that all surfaces of the workpieces are exposed to the blast action.

A device such as the basket 16 will of course be advantageously used whenever the workpieces are of relatively small size and otherwise best suited to that typ of support; although it will of course be understood that other types of workpieces may more advantageously be treated by simply mounting them upon a flat rotating table (in lieu of the basket 16) which will be driven by the same arrangement so that the various surfaces of the workpieces will be thereby presented to the *blast stream as explained hereinabove. Thus, for example, a simple table device having a central hub portion adapted to slip-fit downwardly upon the stub axle 12 may be supplied in conjunction with the basket device 1516 as shown herein, for alternative use in connection with different types of workpieces.

It will of course be appreciated that a gear mechanism may be readily employed in conjunction with the drive wheel 14 and the workpiece support basket 16, in order to provide any preferred speed of rotation of the basket relative to the speed of rotation of the end plates 6, 6. Or, in lieu thereof, the distance between the zone of contact of the driving wheel 14 with the end disc 16 relative to the center of rotation of the end disc may be varied; such as by making the vertical branch portion of the arm 12 to be extensible-contractible so that the distance 20 may be adjusted to provide any preferred speed of rotation of the basket. Or, to provide increased speed of basket rotation, the drive wheel p rtion 14 may be mounted below the horizontal level of the support arm 11 and in the region of the bottom peripheral elevation of the end plate 6.

By virtue of the mounting of the workpiece support table and/ or basket by means of its support arm 11 up n the door 8, provision is thus made for facilitating loading and unloading of the workpiece support device. When the door is opened the workpiece sup-port table or basket is thereby automatically withdrawn into the open for maximum accessibility incidental to loading and unloading thereof. However, it will be understood that in lieu of this arrangement, the support arm might be based upon any other portion of the machine casing, such as on one of the side walls thereof, and s dimensioned that the workpiece support table may still be swung out of the casing 1, when the door is open.

It is to be understood of course that the workpiece support belt 2 may be of any preferred form such as comprised of a series of articulated metal plates, or in the form of an endless rubber belt, or the like. In any case the belt will preferably be of perforate form so as to provide suflicient openings to permit the spent blast media to fall therethrough after it has operated upon the workpieces supported by the belt. Also, it is to be understood that whereas in FIGS. 1-3 the workpiece support table is illustrated to be arranged for rotation about a vertical axis, the device may be readily modified so as to incline the axis of table rotation away from the vertical so as to give the workpieces any preferred tumbling action and attitude towards the direction of blast media projection. For example, the support arm pivot pin may be carried by bearing devices arranged so as to incline the pin away from the vertical, while still being parallel to the door 8; the workpiece support table and basket 16 being correspondingly inclined away from the vertical. In such case, the support arm and basket assembly will automatically tend, in response to the forces of gravity, to slide down hill until the rim of the guide wheel 14 rests in friction bearing relation against the end plate 6, thereby eliminating need for any tension spring such as indicated at 19 in the drawing herewith.

FIGS. 4, 5, illustrate another arrangement for mounting the workpiece support table-basket. In this case the support arm 27 is formed to include a vertical portion terminating in a horizontally bent end portion 2711 which is journal'led in a bearing block 28 suspended from the roof of the casing. A locking pin 38 is slip-fitted through an aperture formed in the end of the support arm portion 271: for quick detachable mounting and dismounting of the support arm and the basket, as may be desired. Thus, the machine may be readily converted for use either as a barrel blast machine or as a table blast machine. A tension spring as indicated at 29 may be employed to bias the support arm and the driving wheel 14 against one of the end plates of the machine for driving rotation of the workpiece carrying basket, as explained hereinabove. Or, in the alternative, the bearing block 23 may be so arranged that the weight of the support arm and of the workpiece support mechanism and of the workpieces therein will operate automatically to bias the driving wheel 14 into bearing contact against one of the side plates of the machine.

FIGS. 6, 7, illustrate still another form of mounting for the workpiece support table-basket device, wherein the support arm 30 includes a vertical extension 30b which is journalled in a rotatable coupling 39 suspended from a fixed arm 30a which is fixedly mounted in the roof of the casing. Thus, when the door 8 is open, the support arm 30 may be swung from the operative position shown in FIG. 7 outwardly to the loading-unloading position thereof as shown in broken lines in 4 I FIG. 7. In this case a tension spring or a torsion spring in connection with the coupling 39 may be employed if required to bias the driving wheel 14 into bearing contact with one of the side plates 6, for the purposes explained hereinabove.

FIGS. 8, 9, 10, of the drawing herewith illustrate still another embodiment of the workpiece support table driving mechanism, wherein a speed change gear is provided in combination with the workpiece support table. In this case a carrier arm 31 is provided to extend rigidly from the door 8, and the arm 31 mounts a two-armed bell crank 32. One arm of the bell crank as indicated at 32a carries at its outer end a drive wheel 33, and an endless friction cord 34- is trained about the wheel 33 and around a second wheel 35 which is keyed to the workpiece carrying basket 36. The other arm 32b of the bell crank 32 is biased by means of a tension spring 37 connected to the support arm 31, and the parts are so arranged that the tension of the spring 37 operates to bias the drive wheel 33 into friction bearing relation against one of the end plates 6 of the machine (FIGS. 9, 10). Thus, rotation of the side plates 6 frictionally drives the endless cord 34, which in turn causes the basket 36 to rotate; the speed of rotation of the basket depending upon the ratio between the distance between the position of driving contact and the center of rotation of the side plate 6, and the diameter of the wheel 35. By virtue of such an arrangement, the basket 16 may be driven to rotate at a speed considerably faster than in connection with the form of the invention previously illustrated and described.

It is of course to be understood that whereas the workpiece support table is illustrated and described above as being in all cases driven by frictional contact with one of the side plates 6, the table may be driven by some other suitable rotating or revolving element of the barrel blasting machine; such as for example by hearing contact against the feed belt 2. In any case, it will be appreciated that it is a particular feature of the present invention that a single machine is thereby provided whichis readily convertible for use either as a barrel blast type machine or as a table blast type machine; the conversion thereof being quickly effected with utmost facility so that the single machine will readily serve the purposes of two different type machines such as have been heretofore required.

What is claimed is:

1. In combination with a tumbling machine including a casing, horizontally disposed roller means journalled in said casing, a pair of laterally spaced disc-like side plates journalled in said casing, endless conveyor means trained over said roller means and beneath said side plates to provide a workpiece tumbling pocket, means for rotating said roller means and said side plates and effecting movement of said conveyor means, and a blast media projection device mounted on said casing above said conveyor means for directing blasting media downwardly into said pocket; a support member detachably mounted on said casing, a horizontally disposed workpiece support member journalled on said support member for rotation about a generally upright axis at a position beneath said blast media projection device, and means for rotating said workpiece support member including a driven member movable into and out of driven engagement with one of said side plates.

2. The assembly as defined in claim 1 wherein said support member is pivotally mounted on said casing for swinging said workpiece support member toward and away from said one side plate, and said means comprising a drive wheel rigid with said support. member and being larger than such support member to engage said one side plate.

3. The assembly as defined in claim 2 wherein said casing is provided with an access door, said support memher being pivotally mounted on said access door, and

spring means biasing said support member to engage said drive wheel with said one side plate when the access door is closed.

4. In combination with a tumbling machine including a casing, horizontally disposed roller means journalled in said casing, a pair of laterally spaced disc-like side plates journalled in said casing, endless conveyor means trained over said roller means and beneath said side plates to provide a workpiece tumbling pocket, means for rotating said roller means and said side plates and effecting movement of said conveyor means, and a blast media projection device mounted on said casing above said conveyor means for directing blasting media downwardly into said pocket; workpiece supporting means including a substantially horizontal workpiece support member for selective disposition beneath said blasting media device, a support arm connected to said casing and rotatably receiving said support member for rotation about a generally vertical axis, and means for rotating said support member.

5. The assembly as defined in claim 4 wherein the last means engages one of said plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,882,44 2 Peik Oct. 11, 1932 2,429,742 Barnes Oct. 28, 1947 FOREIGN PATENTS 580,226 Great Britain Aug. 30, 1946 

